Numbers k such that (10^(2k+1) - 6*10^k - 1)/3 is prime.

Terms

a(0) =1a(1) =3a(2) =7a(3) =61a(4) =90a(5) =92a(6) =269a(7) =298a(8) =321a(9) =371a(10) =776a(11) =1567a(12) =2384a(13) =2566a(14) =3088a(15) =5866a(16) =8051a(17) =9498a(18) =12635a(19) =24512a(20) =32521a(21) =43982